Establishment of a Refined Brain Model for Evaluating Implantation Behavior of Neural Electrode and Research of its Simulated Behavior

The long-term reliability of the neural electrode is closely related to its implantation behavior.In orderto realize the quantitative research of the implantation behavior in a low-cost and accurate way,a refined brainmodel containing meninges is proposed.First,the expected simulation material was selected through measuringthe elastic modulus based on the method of atomic force microscope indentation technique.As a result,the 2%(mass fraction)agarose gel simulated the gray and white matter,the 7:1(volume ratio)polydimethylsiloxane(PDMS)sheet simulated the pia mater,and the polyvinyl chloride(PVC)film simulated the dura mater.Second,based on designing a three-layer structure mold,the brain model was prepared by inverted pouring to realizea flat implantation surface.Finally,the simulation behavior of the brain model was investigated with the ratbrain as a reference.For mechanical behavior of implantation,the implantation force experienced two peaks bothin the brain model and the rat brain,maximum values of which were 10.17 mN and 7.69 mN respectively.Thelarger implantation force in the brain model will increase the strength requirement for the electrode,but reducethe risk of buckling of that in practical application.For humoral dissolution behavior,the dissolution rates ofthe polyethylene glycol(PEG)coating of the electrode in the brain model and rat brain were 7000μm3/s and5600μm3/s,respectively.The faster dissolution rate in the brain model will cause the larger thickness of thecoating design but provide sufficient implantable time in practical application.The establishment of the brainmodel and the research of its simulated behavior are beneficial to the size design of the electrode substrate andcoating,and research of the implantation mechanism,and further increase the functional life of the electrode.

Emerging personalized virtual brain models: next-generation resection neurosurgery for drug-resistant epilepsy?

Recently,a novel workflow known as the virtual epileptic patient(VEP)has been proposed by a research team from Aix Marseille Universitéin their papers published in Lancet Neurology,Science Translational Medicine and Epilepsia.This method involves creating an individualized virtual brain model based on computational modelling,which can facilitate clinical decision-making by estimating the epileptogenic zone and performing the virtual surgery.Here,we summarize brief workflow,strengths,and limitations of VEP,as well as its performance in a retrospective study of 53 patients with drug-resistant focal epilepsy who underwent stereoelectroencephalography.A large-scale clinical trial(NCT03643016)is underway to further assess VEP,which is expected to enroll 356 patients prospectively.As supporting evidence accumulates,the clinical application of VEP has the potential to improve clinical practice,leading to better outcomes and qualities of life of patients.

BRAIN INJURY BIOMECHANICS IN REAL WORLD VEHICLE ACCIDENT USING MATHEMATICAL MODELS

This paper aims at investigating brain injury mechanisms and predicting head injuries in real world accidents. For this purpose, a 3D human head finite element model （HBM-head） was developed based on head-brain anatomy. The HBM head model was validated with two experimental tests. Then the head finite element（FE） model and a multi-body system （MBS） model were used to carry out reconstructions of real world vehicle-pedestrian accidents and brain injuries. The MBS models were used for calculating the head impact conditions in vehicle impacts. The HBM-head model was used for calculating the injury related physical parameters, such as intracranial pressure, stress, and strain. The calculated intracranial pressure and strain distribution were correlated with the injury outcomes observed from accidents. It is shown that this model can predict the intracranial biomechanical response and calculate the injury related physical parameters. The head FE model has good biofidelity and will be a valuable tool for the study of injury mechanisms and the tolerance level of the brain.

Novel rodent models of penetrating traumatic brain injury

A penetrating traumatic brain injury（pTBI）occurs when an object impacts the head with sufficient energy to penetrate skin,cranial bone and meninges to inflict injury directly to the brain parenchyma.This type of injury is particularly common in areas plagued by armed conflicts or gun-related violence.

Expression of hypoxia inducible factor-1 alpha and ischemic erythropoietin tolerance in the brain of cerebral ischemic tolerance model rats

BACKGROUND： Hypoxia inducible factor-1 alpha （HIF-1 （x） and erythropoietin（EPO）, possessing neuroprotective effect in the cerebral ischemia, might play an important role in the formation of cerebral ischemic tolerance （IT）. OBJECTIVE：To observe the neuroprotective effect of cerebral ischemic preconditioning（IPC） of rats, and the expression and mechanism of HIF-1α and target gene erythropoietin in the brain tissue following the formation of cerebral IT. DESIGN ： A randomized and controlled observation SETTING： Department of Neurology, the Affiliated Hospital of Medical College, Qingdao University MATERIALS： Totally 84 enrolled adult healthy male Wistar rats of clean grade, weighing 250 to 300 g, were provided by the Animal Experimental Department, Tongji Medical College of Huazhong University of Science and Technology. Ready-to-use SABC reagent kit and rabbit anti-rat HIF-1α monoclonal antibody were purchased from Boshide Bioengineering Co.Ltd （Wuhan）; Rabbit anti-rat EPO monoclonal antibody was purchased from Santa Cruz Company （USA）. METHODS： This experiment was carried out in the Department of Anatomy, Medical College, Qingdao University during March 2005 to March 2006. ① The 84 rats were divided into 3 groups by a lot： IPC group （n=40）, sham-operation group （n=40） and control group （n=4）. In the IPC group, middle cerebral artery was occluded for 2 hours respectively on the 1^st, 3^rd, 7^th, 14^th and 21^st days of the reperfusion following 10-minute preischemia was made using a modified middle cerebral artery second suture method from Zea-Longa. The rats were sacrificed 22 hours after reperfusion in the end of middle cerebral artery occlusion （MCAO）. That was to say, after 10-minute preischemia, suture was exited to the extemal carotid artery and embedded subcutaneously. Middle cerebral artery was occluded again to form the second reperfusion at the set time point after reperfusion. Twenty-two hours later, rats were sacrificed; In the sham-operation group,the preischemia was substituted by sham-operation（only common carotid artery and crotch were exposed, and MCAO by suture was omitted）, and the other procedures were the same as those in the IPC group. In the control group, rats were given sham-operation twice at an interval of one day, and they were sacrificed 24 hours after the second sham-operation. ② Brain tissue was taken from the rats in each group. Cerebral infarction area of each layer was measured with TTC staining, and total cerebral infarction volume （The total cerebral infarction area of each layerxinterspace ） was calculated. After brain tissue was stained by haematoxylin-esoin （HE）, the form of nerve cells was observed under an optical microscope, and the expressions of HIF-1α（and EPO protein in the brain tissue were detected with immunohistochemical method. MAIN OUTCOME MEASURES： ①Cerebral infarction volume;②form of nerve cell; ③ the expression of HIF-1α and EPO protein in the brain tissue. RESULTS：Totally 84 rats were enrolled in the experiment. The dead rats were randomly supplied during the experiment, and finally 84 rats entered the stage of result analysis. ① Detection of cerebral infarction volume of rats in each group： Cerebral infarction volume in the IPC group was significantly smaller than that in the sham-operation group on the 1^st, 3^rd and 7^th days after reperfusion respectively [（161.2±6.9） mm^3 vs （219.9±11.2） mm^3, （134.9±9.0） mm^3 vs （218.6±13.0） mm^3, （142.9±13.7） mm^3 vs （221.3±14.2） mm^3, t=-8.924, 10.587,7.947, P〈 0.01]. ② Observation of nerve cell form of brain tissue： HE staining showed that the ischemic degree, range and cerebral edema degree of IPC group were significantly milder than those of sham-operation group. ③ The expressions of HIF-1α and EPO protein in cerebral cortex and hippocampus ： The expression of HIF-1αof IPC group was significantly higher than that of sham-operation group on the 1^st, 3^rd and 7^th days after reperfusion respectively （125.93±3.79 vs 117.65±5.60, 140.63±4.64 vs 119.33±4.26, 131.15±2.74 vs 107.60±3.89, t=2.449, 6.763,9.899,P 〈 0.05-0.01）. The expression of EPO of IPC group was significantly higher than that of sham-operation group on the 3^rd and 7^th days after perfusion respectively （141.68±3.29 vs 126.33±4.51, 138.88±2.59 vs 125.58±6.18,t=5.499,3.970, P〈 0.05）. CONCLUSION ： ①IPC can protect the never cells in rat brain and the best time to onset of cerebral IT induced by IPC is 1 to 7 days after reperfusion. ② Neuroprotective effect of cerebral IT might be related to the expression of HIF-1α and its target gene EPO.

Susceptibility-weighted imaging is suitable for evaluating signal strength in different brain regions of a rabbit model of acute hemorrhagic anemia

Acute hemorrhagic anemia can decrease blood flow and oxygen supply to brain, and affect its physiological function. While detecting changes in brain function in patients with acute hemorrhagic anemia is helpful for preventing neurological complications and evaluating therapeutic effects, clinical changes in the nervous systems of these patients have not received much attention. In part, this is because current techniques can only indirectly detect changes in brain function following onset of anemia, which leads to lags between real changes in brain function and their detection.

Effects of exercise on brain functions in diabetic animal models

Human life span has dramatically increased over several decades,and the quality of life has been considered to be equally important.However,diabetes mellitus(DM) characterized by problems related to insulin secretion and recognition has become a serious health problem in recent years that threatens human health by causing decline in brain functions and finally leading to neurodegenerative diseases.Exercise is recognized as an effective therapy for DM without medication administration.Exercise studiesusing experimental animals are a suitable option to overcome this drawback,and animal studies have improved continuously according to the needs of the experimenters.Since brain health is the most significant factor in human life,it is very important to assess brain functions according to the different exercise conditions using experimental animal models.Generally,there are two types of DM; insulin-dependent type 1 DM and an insulin-independent type 2 DM(T2DM); however,the author will mostly discuss brain functions in T2 DM animal models in this review.Additionally,many physiopathologic alterations are caused in the brain by DM such as increased adiposity,inflammation,hormonal dysregulation,uncontrolled hyperphagia,insulin and leptin resistance,and dysregulation of neurotransmitters and declined neurogenesis in the hippocampus and we describe how exercise corrects these alterations in animal models.The results of changes in the brain environment differ according to voluntary,involuntary running exercises and resistance exercise,and gender in the animal studies.These factors have been mentioned in this review,and this review will be a good reference for studying how exercise can be used with therapy for treating DM.

An improved memristor model for brain-inspired computing

Memristors, as memristive devices, have received a great deal of interest since being fabricated by HP labs. The forgetting effect that has significant influences on memristors＇ performance has to be taken into account when they are employed. It is significant to build a good model that can express the forgetting effect well for application researches due to its promising prospects in brain-inspired computing. Some models are proposed to represent the forgetting effect but do not work well. In this paper, we present a novel window function, which has good performance in a drift model. We analyze the deficiencies of the previous drift diffusion models for the forgetting effect and propose an improved model. Moreover,the improved model is exploited as a synapse model in spiking neural networks to recognize digit images. Simulation results show that the improved model overcomes the defects of the previous models and can be used as a synapse model in brain-inspired computing due to its synaptic characteristics. The results also indicate that the improved model can express the forgetting effect better when it is employed in spiking neural networks, which means that more appropriate evaluations can be obtained in applications.

Granulocyte-colony stimulating factor suppresses early inflammatory response of striatum in a cardiopulmonary bypass-circulatory arrest model of ischemic brain injury in newborn piglets

We investigated the effect of Granulocyte-Colony Stimulating Factor (G-CSF) on expression of pro- and anti-inflammatory proteins in the striatum of new- born piglet brain following cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA). Piglets were placed on CPB, cooled to 18?C, subjected to 30 min of DHCA and 1 h of low-flow (20 ml/kg/min), rewarmed to 37?C, separated from CPB circuit and monitored for 2 h. Striatum was then isolated for protein analysis. The levels of proteins are presented relative to the mean in the control group (mean ± SEM, n = 6). DHCA increased the levels of pro-inflammatory proteins: IL-1alpha (158% ± 23%, P = 0.05), IL-6 (152% ± 16%, P = 0.03), TNF-alpha (144% ± 2%, P = 0.003), MIP-3 alpha (148% ± 12.6%, P = 0.03), NAP-3 (216% ± 16%, P = 0.05), GRO (165% ± 19%, P = 0.03) and BLC (140.4 ± 15%, P = 0.05). Compared to DHCA, the G-CSF-treated group had significantly decreased levels of IL-6 (110.8% ± 11% vs. 152% ± 16%, P = 0.05), TNF-alpha (120.6% ± 5.4% vs. 144% ± 2%, P = 0.001), MIP-3 alpha (148% ± 12.6% vs. 104.8% ± 13%, P = 0.02) and NAP-2 (216% ± 16% vs. 122% ± 23%, P = 0.002). The levels of anti-inflammatory proteins did not change in DHCA group compared to control, except for VEGF which decreased to 37.5% ± 9%, P = 0.003. The levels of all protective proteins in the G-CSF group increased versus the DHCA group, but the increases did not attain a P value of 0.05. Conclusions: In an immature brain subjected to circulatory arrest, the early inflammatory response in the striatum is diminished by pretreatment with G-CSF.

Anesthesia-induced neurotoxicity in an animal model of the developing brain:mechanism and therapies

Children are being exposed to an increasingly greater variety of anesthetics with advances in pediatric and obstetric surgery. Recent animal and retrospective human data suggest that the general anes- thetics commonly used in pediatric medicine could he damaging to the developing brain when used at clinical concentrations. In viw~ primate and rodent models have shown that neonatal exposure to clinical concentrations of anesthetics causes neural apoptosis and long-term cognitive impairment. Many general anesthetics.

Differences in pathological changes between two rat models of severe traumatic brain injury

The rat high-impact free weight drop model mimics the diffuse axonal injury caused by severe traumatic brain injury in humans,while severe controlled cortical impact can produce a severe traumatic brain injury model using precise strike parameters.In this study,we compare the pathological mechanisms and pathological changes between two rat severe brain injury models to identify the similarities and differences.The severe controlled cortical impact model was produced by an electronic controlled cortical impact device,while the severe free weight drop model was produced by dropping a 500 g free weight from a height of 1.8 m through a plastic tube.Body temperature and mortality were recorded,and neurological deficits were assessed with the modified neurological severity score.Brain edema and bloodbrain barrier damage were evaluated by assessing brain water content and Evans blue extravasation.In addition,a cytokine array kit was used to detect inflammatory cytokines.Neuronal apoptosis in the brain and brainstem was quantified by immunofluorescence staining.Both the severe controlled cortical impact and severe free weight drop models exhibited significant neurological impairments and body temperature fluctuations.More severe motor dysfunction was observed in the severe controlled cortical impact model,while more severe cognitive dysfunction was observed in the severe free weight drop model.Brain edema,inflammatory cytokine changes and cortical neuronal apoptosis were more substantial and blood-brain barrier damage was more focal in the severe controlled cortical impact group compared with the severe free weight drop group.The severe free weight drop model presented with more significant apoptosis in the brainstem and diffused blood-brain barrier damage,with higher mortality and lower repeatability compared with the severe controlled cortical impact group.Severe brainstem damage was not found in the severe controlled cortical impact model.These results indicate that the severe controlled cortical impact model is relatively more stable,more reproducible,and shows obvious cerebral pathological changes at an earlier stage.Therefore,the severe controlled cortical impact model is likely more suitable for studies on severe focal traumatic brain injury,while the severe free weight drop model may be more apt for studies on diffuse axonal injury.All experimental procedures were approved by the Ethics Committee of Animal Experiments of Tianjin Medical University,China(approval No.IRB2012-028-02)in Febru ary 2012.

Effects of Chuanxiongqin hydrochloride on increasing the fluidity of brain cell membrane and scavenging free radicals in model rats with ischemia/reperfusion injury

BACKGROUND: The fluidity of cell membrane can be affected by various factors. Many experiments have confirmed that the ischemia/reperfusion of organic tissue can increase the contents of free radicals, which lead to high rigidity and low fluidity of cell membrane, and the conditions can be changed by Chuanxiongqin. OBJECTIVE: To observe the effect and mechanism of Chuanxiongqin hydrochloride on the fluidity of brain cell membrane in rat models of ischemia/reperfusion. DESIGN: A completely randomized controlled animal trial. SETTINGS: Institute of Brain Sciences; Department of Physiology, Medical College, Datong University. MATERIALS: Twenty male grade Ⅰ Wistar rats of 170-220 g were randomly divided into model group (n =10) and control group (n =10). Chuanxiongqin hydrochloride (molecular mass was 172.2) was purchased from the National Institute for the Control of Pharmaceutical and Biological Products (batch number: 0817-9803); Spin labelers: 5-doxyl-stearlic acid methylester (5DS), 16-doxyl-stearlic acid methylester (16DS), xanthine, xanthine oxidase (XOD) and 5,5-dimeth-1-pyrroline- N-oxide (DMPO) from Sigma Company; Bruker ESP 300 electron paramagnetic resonance (EPR) spectrometer by Bruker Company (Germany). METHODS: The experiments were carried out in the State Key Laboratory of Natural and Biomimetic Drugs, Peking University from June 2001 to July 2002. In the model group, rats were made into models of cerebral ischemia by 30-minute ligation and 2-hour reperfusion of common carotid arteries; The rats in the control group were not made into models. The order parameter (S) and rotational correlation time (τc) were detected with the ESR spectrometer by means of spin labeling. The greater the S and τc, the smaller the fluidity. Meanwhile, the clearance rate of free radicals was detected with ESR spin trapping. The measurement data were compared using the t test. MAIN OUTCOME MEASURES: The S, τc and clearance rates of O2 · and OH· free radicals were compared between the model group and control group. RESULTS: The S and τc in the model group [0.738 4±0.003 5; (8.472±0.027)×10-10 s/circle] were obviously different from those in the control group [0.683 9±0.008 3; (7.945±0.082)×10-10 s/circle, t =5.731, 5.918, P < 0.05], which suggested that ischemia/reperfusion injury decreased the fluidity of brain cell membrane. After adding Chuanxiongqin hydrochloride, there were no obvious differences between the model group [0.688 5±0.030 5; (7.886±0.341)×10-10 s/circle] and control group (P > 0.05), indicating that Chuanxiongqin hydrochloride could recover the fluidity of brain cell membrane after ischemia/reperfusion injury close to the level in the normal control group. Chuanxiongqin hydrochloride could directly scavenge the O2 · and OH· free radicals, and the maximal clearance rates were 83.92% and 44.99% respectively. CONCLUSION: Chuanxiongqin hydrochloride increases the fluidity of membrane of ischemia-injured brain cell by scavenging both O2 ·and OH· free radicals.

Using induced pluripotent stem cells derived neurons to model brain diseases

The ability to use induced pluripotent stem cells（i PSC）to model brain diseases is a powerful tool for unraveling mechanistic alterations in these disorders.Rodent models of brain diseases have spurred understanding of pathology but the concern arises that they may not recapitulate the full spectrum of neuron disruptions associated with human neuropathology.iPSC derived neurons,or other neural cell types,provide the ability to access pathology in cells derived directly from a patient＇s blood sample or skin biopsy where availability of brain tissue is limiting.Thus,utilization of iPSC to study brain diseases provides an unlimited resource for disease modelling but may also be used for drug screening for effective therapies and may potentially be used to regenerate aged or damaged cells in the future.Many brain diseases across the spectrum of neurodevelopment,neurodegenerative and neuropsychiatric are being approached by iPSC models.The goal of an iPSC based disease model is to identify a cellular phenotype that discriminates the disease-bearing cells from the control cells.In this mini-review,the importance of iPSC cell models validated for pluripotency,germline competency and function assessments is discussed.Selected examples for the variety of brain diseases that are being approached by iPSC technology to discover or establish the molecular basis of the neuropathology are discussed.

The pig as a preclinical traumatic brain injury model:current models,functional outcome measures,and translational detection strategies

Traumatic brain injury(TBI) is a major contributor of long-term disability and a leading cause of death worldwide. A series of secondary injury cascades can contribute to cell death, tissue loss, and ultimately to the development of functional impairments. However, there are currently no effective therapeutic interventions that improve brain outcomes following TBI. As a result, a number of experimental TBI models have been developed to recapitulate TBI injury mechanisms and to test the efficacy of potential therapeutics. The pig model has recently come to the forefront as the pig brain is closer in size, structure, and composition to the human brain compared to traditional rodent models, making it an ideal large animal model to study TBI pathophysiology and functional outcomes. This review will focus on the shared characteristics between humans and pigs that make them ideal for modeling TBI and will review the three most common pig TBI models–the diffuse axonal injury, the controlled cortical impact, and the fluid percussion models. It will also review current advances in functional outcome assessment measures and other non-invasive, translational TBI detection and measurement tools like biomarker analysis and magnetic resonance imaging. The use of pigs as TBI models and the continued development and improvement of translational assessment modalities have made significant contributions to unraveling the complex cascade of TBI sequela and provide an important means to study potential clinically relevant therapeutic interventions.

Animal model of repetitive mild traumatic brain injury for human traumatic axonal injury and chronic traumatic encephalopathy

Chronic traumatic encephalopathy（CTE）is a chronic neurodegenerative disease featured with tauopathy.CTE is tightly related with repetitive mild traumatic brain injury（m TBI）,which is interchangeably known as concussion（Mc Kee et al.,2009,2013）.This disease is differentiated by neuropathological features from other neurological diseases that involve tau protein aggregation and tangle formation abnormalities like Alzheimer＇s disease （AD）, frontotemporal dementia, and Parkinson- ism linked to chromosome 17 （FTDP-17）.

Effect of glutathione on brain nitric oxide levels in an experimental epilepsy mouse model

BACKGROUND： Oxidative stress plays an important role in the pathophysiology of epilepsy. Glutathione, known as one of the compounds of antioxidant defense, has been shown to inhibit convulsions. Nitric oxide has a proconvulsant effect on a pentylenetetrazole-induced animal model. OBJECTIVE： To evaluate the effects of glutathione administration on nitric oxide levels in brain regions of convulsive and kindling pentylenetetrazole-induced seizure models. DESIGN, TIME, AND SETTING： A randomized, controlled, animal experiment. The study was performed at the Department of Physiology, Gaziantep University and Department of Chemistry-Biochemistry,Kahramamaras Sutcu Imam University in 2006. MATERIALS： Pentylenetetrazole and glutathione were purchased from Sigma, USA. METHODS： A total of 80 mice were assigned to 8 groups （n = 10）： normal control, saline control （1 mL normal saline）, convulsive pentylenetetrazole （single intraperitoneal administration of pentylenetetrazole, 60 mg/kg）, convulsive pentylenetrazole plus glutathione （single administration of 60 mg/kg pentylenetetrazole and 200 mg/kg glutathione）, five-dose glutathione （intraperitoneal injection of 200 mg/kg glutathione respectively at 1, 3, 5, 7, and 10 days）, single-dose glutathione （single administration of 200 mg/kg glutathione）, pentylenetetrazole kindling （intraperitoneal administration of pentylenetetrazole of 40 mg/kg at 1,3, 5, 7, and 10 days）, and pentylenetetrazole kindling plus glutathione group （intraperitoneal injection of 40 mg/kg pentylenetetrazole and 200 mg/kg glutathione respectively at 1, 3, 5, 7, and 10 days）. MAIN OUTCOME MEASURES： All mice were sacrificed 1 hour after the last administration. Brain nitric oxide levels were determined by spectrophotometry. RESULTS： There were no significant differences in nitric oxide levels between the normal control, saline control, five-dose glutathione, and single-dose glutathione groups （P 〉 0.05）. Nitric oxide levels in the cerebral hemisphere and cerebellum were significantly less in the convulsive pentylenetetrazole group, compared with the convulsive pentylenetetrazole plus glutathione group （P 〈 0.01）, and levels in the pentylenetetrazole kindling group were remarkably greater than the remaining groups （P 〈 0.01 ）. Brain nitric oxide levels in all groups gradually decreased from the right brain stem to the left brain stem, cerebellum, left cerebral hemisphere, and right cerebral hemisphere. CONCLUSION： Glutathione regulated nitric oxide levels in various brain regions of pentylenetetrazole-induced kindling models, and did not affect nitric oxide levels in the control mice. These results indicated that glutathione played a role when nitric oxide was over-produced. In addition, the brain stem exhibited the highest levels of nitric oxide in both control mice and pentylenetetrazole-induced kindling models.

A Semi-automatic method for segmentation and 3D modeling of glioma tumors from brain MRI

This work presents an efficient method for volume rendering of glioma tumors from segmented 2D MRI Datasets with user interactive control, by replacing manual segmentation required in the state of art methods. The most common primary brain tumors are gliomas, evolving from the cerebral supportive cells. For clinical follow-up, the evaluation of the preoperative tumor volume is essential. Tumor portions were automatically segmented from 2D MR images using morphological filtering techniques. These segmented tumor slices were propagated and modeled with the software package. The 3D modeled tumor consists of gray level values of the original image with exact tumor boundary. Axial slices of FLAIR and T2 weighted images were used for extracting tumors. Volumetric assessment of tumor volume with manual segmentation of its outlines is a time-consuming process and is prone to error. These defects are overcome in this method. Authors verified the performance of our method on several sets of MRI scans. The 3D modeling was also done using segmented 2D slices with the help of medical software package called 3D DOCTOR for verification purposes. The results were validated with the ground truth models by the Radiologist.

人脑替代模型研究的伦理和治理建议

[背景]人脑组织无疑是分析人脑发育和疾病机制的最佳资源,但人脑的研究长期面临样本获取困难及人类胚胎研究受限于“14天原则”的困境.近年来神经科学家们开发了新型人脑模型,为预防、治疗导致人类痛苦的神经系统疾病和精神疾病带来了希望.该领域迅猛发展的同时,也面临着自身固有的道德两难,即在摆脱“不像人脑”困难的同时,因逐渐“太像人脑”而陷入更危险的伦理困境,这也是影响神经科学发展的关键伦理难题之一.[进展]本文首先介绍了脑科学进展和5种人脑替代模型,即基因编辑非人动物、人-非人动物神经嵌合体、人脑类器官、鲜活离体脑组织和类脑人工智能.然后从生命伦理视角出发,系统论述了其所引发的道德地位、死亡判定、知情同意、隐私保护,以及人-非人动物神经嵌合体的福利和利益5个方面的伦理学问题.最后提出6条涉及人脑模型研究的伦理指导原则作为治理框架.[展望]坚持伦理先行风险前瞻,可扭转伦理作为科技活动之外的“旁观者”角色和侧重“事后”反思批判的范式,对推动我国伦理治理体系从被动应对型向主动预防型转变有重要意义,也为参与全球新兴科技伦理治理提供中国方案.

肺癌脑转移患者早期死亡预测模型的构建与验证

目的构建并验证一个模型以预测肺癌脑转移(lung cancer with brain metastases,LCBM)患者确诊后三个月内死亡的风险。方法本研究纳入监测,流行病学和最终结果(Surveillance,Epidemiology and End Results,SEER)数据库内2010年1月至2015年12月期间确诊为LCBM的患者。以是否发生早期死亡为研究终点将患者分为早期死亡组和非早期死亡组。以8∶2为比例将数据分为训练集和验证集。在训练集上采用最小绝对值收缩和筛选算子(least absolute shrinkage and selection operator,LASSO)回归法筛选预测因子,并使用多因素Logistic回归构建预测模型并创建列线图。使用受试者工作特征(receiver operating characteristic,ROC)曲线、校准曲线和临床决策曲线(decision curve analysis,DCA)分别在训练集和验证集上评估模型性能。结果共纳入5035例患者,早期死亡发生率28.3%。LASSO回归筛选出13个变量,Logistic回归最终保留了13个与LCBM患者早期死亡相关的危险因素,包括年龄、从诊断到开始治疗时间、肿瘤大小、肿瘤部位、肿瘤分化程度和组织学类型、T分期、N分期、手术、放疗、化疗、肝转移和骨转移。验证集的一致性指数(concordance index,C-index)为0.84,校准曲线和DCA显示模型具有较好的预测效能和临床净效益。结论基于多因素Logistic回归构建的LCBM患者发生早期死亡的预测模型的区分度较好,能够为临床决策提供一定的帮助。

基于目标导向的护理模式在脑胶质瘤患者中的应用价值及对自护能力的影响

目的探究基于目标导向的护理模式在脑胶质瘤患者中的应用价值及对自护能力的影响。方法选择2020年2月至2022年2月于我院进行手术治疗的117例脑胶质瘤患者为研究对象,以交叉双盲法将其分为常规护理组(52例,常规护理)和目标导向组(65例,基于目标导向的护理模式)。比较两组的护理效果。结果护理后,目标导向组的生活态度、生活目标、自我控制、人际关系、接受与适应评分及总分高于常规护理组(P<0.05)。护理后,目标导向组的汉密尔顿焦虑量表(HAMA)、汉密尔顿抑郁量表(HAMD)、匹兹堡睡眠质量指数(PSQI)、癌症疲乏量表(CFS)、视觉模拟量表(VAS)评分低于常规护理组(P<0.05)。护理后,目标导向组的自我护理能力量表(ESCA)评分高于常规护理组(P<0.05)。目标导向组的护理满意度高于常规护理组(P<0.05)。结论基于目标导向的护理模式在脑胶质瘤患者中的应用价值较高。